3(4h)-oxo-2h-thiaxantheno (9,9alpha,1-ef)-1,4-diazepin-8,8-dioxides



United States Patent Patented Sept. 22, 1970 ice 3,530,116 3(4H)-OX0-2H-THIAXANTHENO (9,9a,1-ef)-1,4- DIAZEPlN-8,8-DIOXIDES Edward L. Engelhardt, Gwynedd Valley, and David C. Remy, North Wales, Pa., assiguors to Merck & (30.,

Inc., Rahway, N.J., a corporation of New Jersey No Drawing. Filed Aug. 21, 1967, Ser. No. 661,784 Int. Cl. C07d 53/02 U.S. Cl. 260-2393 3 Claims ABSTRACT OF THE DISCLOSURE This invention pertains to pharmocologically active compounds of the following structure:

N ELL wherein Y is hydrogen, halo, alkyl, NO perfiuoroalkyl, cyano, RO, RSO R NSO R NCO (R being alkyl, aryl, aralkyl, alkaryl or hydrogen); and R is alkyl, aryl, aralkyl, alkaryl, or hydrogen and R is alkyl, aralkyl or hydrogen. The disclosed process is summarized in the flow sheet at column 2 of the specification. The compounds exhibit antianxiety activity and a depressant effect on the central nervous system.

FIELD OF THE INVENTION This invention relates to novel diazepines. More particularly, this invention relates to a class of diazepines having the diazepine moiety fused to a thiaxantheno tricyclic ring system.

BRIEF SUMMARY OF THE INVENTION The novel compounds of this invention can be represented by Formula I:

but

wherein Y is hydrogen, halo, alkyl, N0 perfiuoroalkyl, cyano, RO, RSO R NSO R NCO--, (R being alkyl, aryl, arakyl, alkaryl, or hydrogen); and R is alkyl, aryl, aralkyl, alkaryl or hydrogen and R is alkyl, aralkyl or hydrogen.

The compounds of this invention are pharmacologically active substances having useful pharmacodynamic properties. Thus in animals they exhibit antianxiety activity and a depressant effect on the central nervous system.

DETAILED DESCRIPTION OF THE INVENTION The compounds of this invention are prepared from starting materials which are either well known or which are all themselves prepared from readily available cornpounds according to procedures apparent to the artskilled. The general procedures for obtaining Compound I are outlined in steps (A) through (E).

In the following reaction sequence R and Y are as previously defined; R is alkyl, aralky or alkaryl; X is halo; X is chlorine or bromine, and X is chlorine, bromine or iodine. It is preferred that the alkyl. groups be lower alkyl (i.e., methyl, ethyl, n-propyl, i-propyl, n-butyl, t-butyl, sec-butyl). Usually the aryl moiety is mononuclear, e.g., phenyl; but polynuclear aryls, such as naphthyl, phenanthryl, anthryl, etc. are within the contemplation of this invention. Preferably the aralkyl, alkaryl, and aryl moieties contain up to about ten carbons. It is also preferred that the halogen be chlorine or bromine.

(IV) X R OHC OX T NHCCHR X D O O Y reflux .li i liquid V ammonia NHCOHR NHz O OY a 1 (I (D ll I \/l\ V. a. m

N/ \NH Step A.This step involves the replacement of the 1- halo substituent with a substituted sulfonyl amino group having the general formula H NSO' -R (wherein R is as previously defined). Generally this: reaction step is carried out in an inert high boiling solvent preferably having a boiling point from about C. to about 250 C., such as nitrobenzene, and using a catalytic agent, such as copper powder, which is the conventional reagent, in the presence of bases, such as sodium acetate, potassium acetate, alkali metal carbonates and other similar Weak bases.

Step B.--This step comprises a conventional hydrolysis in the presence of a strong acid, such as sulfuric acid, and is generally carried out by dissolving the sulfonamide derivative (III) in the heated sulfuric acid followed by quenching in ice. Other strong acids can be employed such as phosphoric and concentrated hydrochloric acid.

Step C.Following hydrolysis, the amine (IV) is reacted with an alpha-halo acyl halide of the formula X R CHCOX' (X X and R are as previously defined). This acylation step involves various methods for removal of the hydrogen halide that is formed, such as combining with a base, such as pyridine, or expelling it as a gas. Various inert organic solvents can be employed. Where pyridine is utilized as the receptor for the hydrogen halide, ether can be employed as a solvent, for example. Where the halide is expelled as a gas, the reaction can be carried out in a solvent, such as benzene, toluene and a wide variety of other inert organic solvents. When an organic base is utilized to neutralize the hydrogen halide, at least one equivalent of the organic base should be employed as the receptor in order to remove all of the hydrogen halide being given off in the reaction and thereby avoid the formation of quaternary salts. The amination is effected by suspending (V) in liquid ammonia and allowing it to reflux under stirring for a sufficient period of time to allow the reaction to proceed to completion. This can be a matter of from one hour to a day.

Step E.This conventional condensation proceeds straightforwardly. For example, where Y is methyl, all that is necessary to effect the condensation and ring closure is melting the crystalline material (VI). In other instances, it may be necessary to effect the reaction under refluxing conditions in such solvents as pyridine and the like. The duration of the reaction depends upon the molecule employed and can be anywhere from a matter of hours to a matter of days for completion.

The foregoing reaction sequence produces compounds of the Formula I wherein R is hydrogen. (Designated Ia in the above reaction sequence.) To prepare compounds wherein R is alkyl or aralkyl, introduction of such a R group into the benzodiazepin Ia can be accomplished according to the method of L. H. Sternback et al., J. Org. Chem. 27, 3788 (1962) and can be represented by the following reaction sequence:

wherein R and R are as defined previously. Thus it can be seen that the foregoing reaction involves the preparation of the sodio derivative of Ia by reaction of Ia with sodium methoxide in a solvent such as dimethylformamide, followed by treatment of this sodio derivative with the alkylating agent, R X, wherein X is a halide, preferably chloride, bromide, iodide, or sulfate or the like conventional alkylating agent to give I. Exemplary of these alkylating agents are methyl iodide, ethyl chloride, propyl bromide, butyl iodide, dimethyl sulfate, diethyl sulfate, dibutyl sulfate, benzyl chloride, and the like.

EXAMPLE I 1,4-dichlorothiaxanthone-10,10-dioxide 1,4-dichlorothiaxanthone (5.5 g.) is suspended in 40 ml. of glacial acetic acid. The mixture is stirred while 4 ml. of hydrogen peroxide is added. The mixture is heated to reflux at a gentle boil for one hour and then allowed to cool overnight.

The next morning the mixture is cooled in an ice bath and filtered. The precipitate is washed with 25 ml. of acetic acid and dried overnight at 65. The mother liquor from the filtration is diluted with ml. of water and the mixture cooled overnight. The precipitated crystals are filtered, washed with acetic acid and dried in a similar manner. The product after recrystallization from glacial acetic acid melts at 183.6 to 185 C. and is 1,4-dichlor0- thiaxanthone-lO,10-dioxide.

EXAMPLE II (A) 1-p-toluenesulfonamido-4-chlorothiaxanthone- 10,10-dioxide Into a flask fitted with a stirrer and a condenser topped with a calcium chloride drying tube is charged 100 mg. of copper powder, 8.35 g. of paratoluenesulfonamide, 4.05 g. of anhydrous potassium acetate, 10.16 g. of 1,4- dichlorothiaxanthone-10,10-dioxide and ml. of nitrobenzene. The mixture is stirred at gentle reflux for 10 hours and then allowed to cool. The nitrobenzene is steam distilled out and the residue is filtered from the boiling water. The residue is ground to a powder and recrystallized once from acetic acid. The product is dried and found to melt at 199-205 C.

(B) 1-amino-4-ch lorothiaxanthone-10,10-di0xide 1 p toluenesulfonamido-4-chlorothiaxanthone-10,10- dioxide (2 g.) is placed in a 50 ml. flask fitted with a mag netic stirrer and a drying tube. 20 ml. of concentrated sulfuric acid is added and the mixture is heated on a steam bath for one hour, after which it is cooled to room temperature and drowned in 200 ml. of water. The mixture is diluted with 10-normal sodium hydroxide until quite basic (pH 910) and the product is isolated by filtration and washed with water and dried. After two recrystallizations from benzene the product melts at 214.5- 217 C.

(C) 1-bromoacetamido-4-chlorothiaxanthone- 10,10-dioxide Into a flask fitted with a reflux condenser and a drying tube is charged 0.285 g. of dry pyridine, 1.025 g. of 1- amino 4-chlorothiaxanthone-10,10-dioxide, 0.725 g. of bromoacetylbromide and ml. of dry ether. The mixture is stirred for 24 hours and then filtered. The precipitate is washed with ether and then with water after which it is suspended in 200 ml. of water, filtered, and washed with ether. After the product is dried it melts at 208210.5 C. with softening at -202 C.

(D) 1-aminoacetamido-4-chlorothiaxanthone-10,10- dioxide Into a flask fitted with a stirrer, gas inlet and Dry Ice condenser is charged 1.09 g. of 1-bromoacetamido-4-chlorothiaxanthone-10,10-dioxide and 100 m1. of liquid ammonia is condensed into the flask. The mixture is then stirred for 6 hours after which the ammonia is allowed to evaporate. Water is then added and the mixture is stirred for 2 hours. The precipitate is filtered off and is washed with water. After drying the product is recrystallized from benzene to produce 1-aminoacetamido-4- chlorothiaxanthone-IO,IO-dioxide, M.P. 199-200 C.

Analysis.Calcd for C H ClN O S (350.80) (percent): C, 51.36; H, 3.16; Cl, 10.10; S, 9.14. Found (percent): C, 51.57; H, 3.33; Cl, 9.90; S, 9.18.

(E) 7-ch1oro-3 (4H -oxo-2H-thiaxantheno (9,9a,1-ef) l,4-diazepin-8,8-dioxide A solution of 0.86 g. of 1-aminoacetamido-4-chlorothiaxanthone-IO,10-dioxide and 10 ml. of pyridine is stirred magnetically and refluxed for 96 hours. The solution is evaporated to dryness in vacuo and the residue is coevaporated with chloroform. The crude solid product is recrystallized several times from a mixture of water and dimethylformamide to give orange crystals of 7- chloro 3(4H) oxo-2H-thiaxantheno (9,9a,1-ef)-1,4-diazepin-8,8-dioxide, M.P. 288.7289.7 C.

AnaIysis.Calcd for C H ClN O S (332.78) (percent): C, 54.14; H, 2.73; Cl, 10.65; S, 9.64? Found (percent): C, 54.10; H, 3.03; Cl, 10.52; S, 9.60.

EXAMPLE III moacetyl bromide. A yellow precipitate formed immediately and the orange crystals of starting material disap- 1P'toluehesulfonamid0-4-methY1thiaXahthohe-10,10- peared. The mixture was stirred overnight. The yellow dioxide precipitate was filtered oil and washed with water and ether, collected and dried. Purification by recrystalliza- Copper powder (167 mg.), 7.11 g. of anhydrous po- 5 tron from benzene gave 1-'bromoacetam1do-4-methylth1atassrum acetate, 14.70 g. of p-toluenesulfonamlde, 106 XanthoneJOlOdioXide M.P. 199400, C-

ml. of nitrobenzene, and 16.77 g. of a mixture of l-chloro-4-methylthiaxanthone-10,10-dioxide and 1-methyl-4- ig f i a i g8? g j 2 chlorothiaxanthone-10,10-dioxide (F. Ul'lrnann and D. von 49 d i i 9 n P Glenck, Ber., 49, 2487 (1916)) were added into a reac- 10 tion flask provided with means for stirring, heating and (D) 1-a i ta id 4- th 1thj a th -1O 1() refluxing. The mixture was heated to reflux for 10 hours, di id after which the reaction mixture was steam distilled to remove nitrobenzene. The hot water was decanted from Into a flask fitted wlth a stlrrer, gas Inlet and y Ice a gummy brown pot residue. This residue was triturated Condenser Was Charged 0 p E-f- 0f 1-bf0m0aetamid0-4- with 100 ml. of hot glacial acid to induce crystallization. methylthlaxahthohe-li),lo'dloxlde from P and P- The crystalline material was removed by filtration and proximately 100 1111- liquid ammonia Was Condensed washed with 200 ml. of glacial acetic acid. B fractional into the flask. The IIllXtuIe Was Stirred r a minimum crystallization from glacial acetic acid, the unreacted 1- of four hours after Which the ammonia s a w d t methyl-4-chlorothiaxanthone-10,10-dioxide was removed evaporate T0 the yellow reSidlle Was added 150 of and 12.4 g. of 1-(p-toluenesulfonamido)-4-rnethylthiax- Water and the mixture stirred to dissolve the ammonium anthone-10,10-dioxide was obtained as small yellow-brown bromide Y-P The mixture Was filtered and the needles, M.P. 2032-2042 C. yellow product washed well with water, collected, and Analysis.-Calcd for C H NO S (273,30) (percent); dried to give 0.35 g. of product melting at 167171 C., C, 59.00; H, 4.01; S, 15.00. Found (percent): C, 58.98; resolidifying at about 175-180 C. and remelting at 289- H, 4.19; S, 15.01. 292 C. (dec.).

(B) 1-amino-4-methylthiaxanthone-10,10-dioxide (E) 7'methyl'3(4H)foxofzfi'thiafxamheno 1,4-d1azep1n-8,8-d1ox1de 1 (p toluenesnlfonamido)-4-methylth1axanthone-10, 3O 10'dioxide (12.21 g.) produced in step (A) and 130 ml, 1-aminoacetamido-4-methylthiaxanthone-10,10-dioxidc of concentrated sulfuric acid was placed in a 300 ml. re- W511S Placed in a flask and immersed in aWOOdS action flask provided with a calcium chloride drying tube metal bath at 180-185 C. for 15 minutes. The solid and magnetic stirrer. The mixture was heated on the melted and then quickly re-solidified. This solid was puri steam bath for 1 hour while stirring, and then cooled to fied by recrystallization from a mixture of water and diroom temperature. The solution was then poured onto methylformamide to give 7-methyl-3 (4H)-oxo-2Hthiax- 1300 ml. of ice and water. The mixture was stirred and antheno (9,9=a,1-ef)-1,4-diazepin-8,8-dioxide as tiny ormade basic by addition of 520 ml. of 10 N sodium hyange plates, M.P. 292294 C. (dec.). droxide. The yellow precipitate was removed-by filtration, Analysis.Calcd for C H N O S (312.36) (percollected, washed by suspension in 1 liter of water, and 4 cent): C, 61.53; H, 3.87; N, 8.97; S, 10.26. Found (perfiltered. The dried product weighed 7.71 g. Recrystalcent): C, 61.53; H, 3.97; N, 8.88; S, 10.38.

lization from benzene gave a red product identified as 1- Using the appropriate starting compounds, the followamino 4-methylthiaxanthone-10,10-dioxide, M.P. 191- ing products of Steps A through E are also prepared as 192 C. above described:

STEP A Formula (II) HZNSOZR1 Product (III) Example X Y R1 Y R1 Br (EH30 p-tolyl CHaO p-tolyl I N02 ethyl NO; ethyl F CFa CH5 CFa CH 01 H benzyl H benzyl Cl CHeSOz CH3 CHnSOz methyl or (CHM-N? p-tolyl (CH3)z-NSO2 p-tolyl Br (CHs)zNCO- CH3 (CHa)z-NCO- CH3 01 ON n-propyl (3N n-propyl Br CH3 B1 CH3 Analysis.Calcd for C H NO C (273.30) (percent): STEP 3 C, 61.52; H, 4.06; S, 11.73. Found (percent): C, 61.79; H) 3.92; S '64. Formula III Product IV 0 1 b t 'd 4 th 1h a1 1010 Example Y Y -ro ceam1o--e nonmoa i yt laxa e 6O 13 orno p-to'lyl c11 0 5 Into a ml. flask equ1pped with magnetic stirrer and 1 emit sulfonyl ben yl ethyilsulfonyl 17 (O2H5)2NSO2 t-butyl (C2H5)2NSO2 condenser with a calcium chloride drying tube was placed oHmNGO CH3 (CHmNCO 1.00 g. of 1-am1no-4-chlorothiaxanthone-10,10-d1ox1de, 0N i-propyl CN 0.305 g. of pyridine, 75 ml. of ether, and 0.811 g. of bro- 65 STEP 0 Formula IV XZRZCHGOX Product V Ex. Y X10 X R Y X R 26 propoxy C1 C1 ethyl propoxy' C1 ethyl 27.- butoxy Br Br butyl butoxy Br butyl 28.. l Cl Br phenyl Cl Br phenyl 29 N0 01 c1 p-tolyl N02 01 p-tolyl 30.- propyl-sulfonyl C1 C1 benzyl propyl-sullonyl Cl benzyl 3L- (CzH5)2NSOz- Cl I H (CzHsh-NSO; I H

STE P D Formula V Formula VI E Y X R Y R 34.-.. propoxy Cl CH3 propoxy CHa 35- butoxy Br ethyl butoxy ethyl 36. Cl Br butyl Cl butyl 37- N02 Cl phenyl N02 phenyl 38 propyl-sulfonyl Cl p-tolyl propyl-sullonyl p-tolyl 39 (C2I'I5)gNSO2 I H (C2H5)2NS02 H 40 (C2H5)z-NCO; C1 propyl (CzI 5)2NCOg propyl 41.... CN Br CH; CN C113 STEP E Formula VI Product Ia Example Y R Y R 01130 11 N02 11 C F phonyl H CH 0113802 CH3 (CH3)2N S02- 11 (CHM-N CO2 bcnzyl CN p-tolyl Br 11 I CH3 F H The compounds of the present invention can be prepared and administered in a wide variety of oral and parenteral dosage forms, singly, or in combination with other coacting compounds. They can, if desired, be associated with a carrier which can be a solid material or a liquid in which the compound is dissolved, dispersed, or suspended. The solid compositions can take the form of tablets, powders, capsules, pills, or the like, preferably in unit dosage forms for simple administration or precise dosages. In general the daily dosages range from about 10 mg. to about 500 mg. The liquid composition can take the form of solutions, emulsions, suspensions, syrups, or elixers. Such conventional solid carriers as sucrose, starches, etc. or liquid vehicles such as non-toxic alcohols, glycerine, or the like, may be thus used.

8 We claim: 1. A compound of the formula References Cited UNITED STATES PATENTS 2,629,719 2/1953 Cusic 26O328 3,116,291 12/1963 Petersen et al. 260328 3,294,803 12/1966 Rosi et a1. 260328 3,296,252 1/1967 Frey et al. 260-2393 3,329,676 7/1967 Bell et al. 260239'.3 3,316,251 4/1967 Schmidt 260239.3

HENRY R. JILES,'Primary Examiner R. T. BOND, Assistant Examiner U.S. Cl. X.R.

Patent No. 3,530,116 Dated September 22, 1970 Inventor) Edward L. Engelhardt and David C. Remy It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

r- Title, delete "9,9a" and insert 9,9a

Column 1 line 22, delete "N" and insert N-R Column 2 line 1, delete "aralky" and insert aralkyl Column 4 line 62, delete "9,9a" and insert 9,9a line 71, delete "9,9a" and insert 9 ,9a Column 5 line 16, insert after "glacial" acetic line 24, delete "C H NO S (273. 30) and insert C H NO S (427.48) line 56 delete C H NO C and insert C H NO S Column 6 line 27 delete "9,9a" and insert 9,9a line 37, delete "9 ,9a" and insert 9,9a line 46, Step A, delete "H NSO R and insert H NSO R line 51, Example 8 delete "CH SO and insert CH SO line 74 Example 32, both "Y" columns of Step C, delete "NCO and insert NCO Column 7, line 9, Example 40, both "Y" columns of Step D, delete NCO and insert NCO line 20, Example 48, both "Y" columns of Step E, delete "NCO and insert NCO Column 8 line 15, insert after "loweralkylsulfonyl" diloweralkylsulfonyl line 19, delete "9,9a" and insert 9,9a line 21, delete "9,9c1 and insert 9,9a

Signed and sealed this 26th day of October 1971.

(SEAL) Attest:

EDWARD M.FLEICHER, J'R. ROBERT GOT'ISCHALK Attestinv, Officer Acting Commissioner of Patents 

